This invention concerns a process for fabricating a reinforced drain cover and reinforced drain covers obtained using this process.
In particular the invention concerns a process for fabricating reinforced drain covers out of plastic.
The purpose of the invention is to provide a process that allows the fabricating of reinforced drain covers that are maximally resistant to warping due to heavy loads, i.e., that ensures that the final product is optimally stabile.
An additional goal of the invention consists in providing reinforced drain covers capable of handling very large loads, for example sewer covers with a diameter of 800 mm capable of handling 40 tons or more.
The invention provides a process of fabricating reinforced drain covers, characterised by the insertion into a mould of number of layers of reinforcement made up of strands of fibre with a predetermined diameter that in turn are made up of interwoven fibres, and lying between these, also in layers, horizontal and vertical spacers, preferably more rigid than the reinforcing fibres; filling the mould with plastic such that all fibres visible at the external perimeter come maximally into contact with the plastic, this by covering the fibre strands on all sides with a plastic layer of a predetermined thickness, and after the hardening of the plastic, removing of now complete reinforced drain covers.
By using the aforementioned structure, as will be seen in more detail below, a balance is provided that allows the reinforced drain cover, after removal from the mould, cooling and the shrinkage caused by such, to meet the stated requirements concerning flatness, shape and
The aforementioned mould is preferably filled with plastic by means of the so-called RIM procedure (Reaction Injection Moulding). With this procedure the plastic enters the mould relatively slowly which offers the advantage, according to the invention, that the reinforcement and the spacers are not subjected to brusque forces which eliminates the risk that they would shift.
The invention also concerns a reinforced drain cover that is fabricated according to the aforementioned process.